I have discovered that Gigabyte's @BIOS utility has another hidden, unique function.
Yesterday, whilst doing routine work on a clients network, I used the @BIOS applet to update the motherboard and chipset drivers.
Upon re-boot, no network connection was available, and had to re-create it with new encryption codes etc. for the router.
Thought it was a one off, but did the same thing at home last night on 3 machines all with Gigabyte boards and had the same issue, knocked out my ADSL too, so had to re-boot the router and then perform the same operation as above.
Not the end of the world but worth knowing....Will email them today about this.